Chapter 43 — Protocol Compendium: FoCUS, FATE, RUSH, FEEL, eFAST

📚 Guideline basis

Spencer KT, et al. ASE focused cardiac ultrasound recommendations (JASE 2013); Via G, et al. International evidence-based recommendations for focused cardiac ultrasound (JASE 2014); Jensen MB, et al. FATE (Eur J Anaesthesiol 2004); Perera P, et al. RUSH (Emerg Med Clin North Am 2010); Breitkreutz R, et al. FEEL (Resuscitation 2010); ATLS eFAST; ERC 2021 and 2025 AHA CPR/ECC guidelines.

Choosing a protocol

Protocols exist to make an examination reproducible under time pressure by a clinician who is not a full-time echocardiographer. They differ in scope, training requirement, and — critically — in what they explicitly do not answer.

Protocol	Scope	Views	Time	Training level	Answers	Does not answer
FoCUS	Binary cardiac questions	4–5	2–5 min	Basic	Effusion, gross LV function, RV:LV, gross volume	Any Doppler quantification, valve severity, filling pressures
FATE	Cardiac + pleural screen	4 cardiac + pleural	3–5 min	Basic	As FoCUS plus pleural fluid, plus a structured comparison against a reference card	Doppler quantification
RUSH	Shock aetiology	~8–10 across cardiac, vascular, abdominal	5–10 min	Basic–intermediate	Shock category (pump / tank / pipes)	Quantitative haemodynamics; valve severity
FEEL	Peri-arrest and arrest	1–2 (subcostal ± parasternal)	≤ 10 s per pause	Basic, with team training	Cardiac standstill vs organised motion, tamponade, gross RV dilatation	Everything else — by design
eFAST	Trauma	5 regions	2–4 min	Basic	Free fluid, haemopericardium, pneumothorax, haemothorax	Organ injury, retroperitoneal bleeding
BLUE	Acute respiratory failure	6 lung points + venous compression	3 min	Basic	Respiratory failure aetiology	Cardiac function
Haemodynamic CCE (this book, Ch 28)	Quantitative shock assessment	Staged, 5–10 min	Advanced	Flow state, ventricular mechanism, fluid responsiveness and tolerance, filling pressures	Definitive structural diagnosis
Comprehensive TTE / TEE	Structural diagnosis	28–60+	20–30 min	Advanced	Everything within the modality's reach	—

Escalation rule: start at the protocol matched to the question, and escalate when the protocol's explicit exclusions cover the thing you now need to know.

FoCUS — Focused Cardiac Ultrasound

Purpose: answer binary, high-consequence questions in an unstable patient.

Views: subcostal four-chamber · subcostal IVC · parasternal long axis · parasternal short axis · apical four-chamber.

The five questions:

Is there a pericardial effusion, and is there tamponade physiology?
Is left ventricular function grossly normal, hyperdynamic, or severely impaired?
Is the right ventricle enlarged relative to the left?
Is the inferior vena cava small and collapsing, or plethoric?
Is there gross, obvious valvular abnormality requiring escalation?

Explicitly out of scope: all Doppler quantification, valve severity grading, filling pressure estimation, prosthetic valve assessment, endocarditis exclusion, aortic dissection exclusion, regional wall motion analysis.

FATE — Focus Assessed Transthoracic Echo

Purpose: a structured cardiac and pleural screen, designed around a laminated reference card of normal and abnormal images for direct comparison.

Sequence: subcostal · apical four-chamber · parasternal long axis · parasternal short axis · bilateral pleural scanning.

Structured questions: obvious pathology? · wall thickness and chamber dimensions? · contractility? · pleural fluid? · Does the image fit the clinical picture?

The final question is the distinctive element and the most useful: FATE explicitly requires the operator to reconcile the images with the clinical assessment rather than reporting them in isolation.

RUSH — Rapid Ultrasound in Shock

Purpose: categorise undifferentiated shock. Organised as pump, tank, pipes.

Component	Windows	Findings and interpretation
Pump	Parasternal long and short axis, apical 4C, subcostal	Effusion/tamponade → obstructive · Hyperdynamic small LV → hypovolaemic or distributive · Severely impaired dilated LV → cardiogenic · Dilated RV with septal shift → obstructive (PE)
Tank	IVC, jugular veins, Morison's pouch, splenorenal, pelvis, lung (B-lines, pleural effusion, pneumothorax)	Flat IVC + dry lungs → underfilled ("tank empty") · Plethoric IVC + B-lines → overfilled ("tank overload") · Free fluid → "tank leaking" · Absent sliding with lung point → "tank compromise"
Pipes	Aorta (suprasternal, parasternal, abdominal), femoral and popliteal veins	Aneurysm or dissection flap → "pipes ruptured" · Non-compressible vein → "pipes clogged" (supports PE)

Composite outputs:

Shock type	Pump	Tank	Pipes
Hypovolaemic	Hyperdynamic, small chambers	Flat IVC, dry lungs, ± free fluid	Normal, or aneurysm
Cardiogenic	Dilated, poorly contracting	Plethoric IVC, B-lines, effusions	Normal
Obstructive	Effusion with collapse, or dilated RV	Plethoric IVC, ± absent sliding	± DVT
Distributive	Hyperdynamic (early), impaired (late)	Normal or variable	Normal; look for a source

FEEL — Focused Echocardiographic Evaluation in Life support

Purpose: integrate a single focused view into the ALS algorithm without degrading CPR.

The rules — these are the protocol:

Probe pre-positioned (subxiphoid or parasternal) before the rhythm check is called.
A dedicated sonographer with no other role in the resuscitation.
A timekeeper counting aloud; the probe leaves the chest at 10 seconds regardless of image quality.
Record a loop; interpret after compressions resume. Never interpret live.
Announce a single conclusion to the team leader in one sentence.

The findings that matter: organised coordinated wall motion (pseudo-PEA — treat as profound shock, prognosis materially better) versus cardiac standstill (true PEA); pericardial effusion with arrest (treat as tamponade); gross RV dilatation — with the caveat that this is a near-universal consequence of arrest of any cause and is not by itself an indication for thrombolysis (Chapter 31).

The 2025 AHA guidelines state that POCUS by experienced professionals during cardiac arrest may be considered to diagnose reversible causes if it can be done without interrupting CPR. Where TEE is available in an intubated patient, it removes the interruption problem entirely.

eFAST

Windows: pericardial (subxiphoid) · right upper quadrant · left upper quadrant · pelvis · bilateral thoracic (anterior for sliding, posterolateral for effusion).

Rules: it is a rule-in test; a negative scan excludes neither haemoperitoneum nor organ injury. In penetrating precordial trauma, a normal pericardial window with a large haemothorax may mean the pericardium is decompressing into the chest. In trauma, small volumes tamponade — grade the physiology, not the volume (Chapter 37).

The haemodynamic CCE protocol

The staged protocol used throughout this book, as a working checklist.

Stage 1 — Focused (2–4 min): is there a mechanical cause?

Subcostal 4C — effusion, tamponade physiology, RV:LV, gross LV

Subcostal IVC — size, variation

PLAX — LV dimensions, gross valve appearance, LVOT diameter (zoomed, harmonics off)

A4C — chamber comparison, gross function

Stage 2 — Haemodynamic (5–10 min): what is the flow state and what will fluid do?

LVOT VTI (A5C or A3C) — record the view used; average ≥3 beats (≥5–10 in AF)

Heart rate, rhythm, blood pressure, vasoactive doses, ventilator settings

Stroke volume, SVI, cardiac output, cardiac index

Ea = 0.9 × SBP / SV

Mitral E and A; septal and lateral e′; E/e′

TR peak velocity; estimated PASP; TAPSE and TAPSE/PASP

RV:LV area ratio; septal motion in PSAX

Hepatic vein Doppler; portal pulsatility if congestion suspected

Fluid responsiveness test — passive leg raise with ΔVTI, or end-expiratory occlusion

Lung B-line count, 8 zones

Stage 3 — Comprehensive (20–30 min): what is the structural diagnosis?

Full ASE view set; all valves with colour and spectral Doppler; biplane Simpson's; 17-segment wall motion; right parasternal window for AS; suprasternal aorta; shunt assessment.

Escalate to TEE if: Stage 2 cannot be completed for window failure · prosthetic mitral valve · suspected endocarditis · suspected dissection · post-cardiotomy tamponade · ECMO or MCS cannula question · appendage thrombus before cardioversion.

Integrated cardiopulmonary sequence

The order in Chapter 41, as a checklist:

Anterior chest bilaterally — sliding, A vs B profile, lung point

Subcostal cardiac — effusion, RV:LV, gross LV

Subcostal IVC

Parasternal and apical — chambers, LVOT VTI, E/e′, TR velocity

Lateral and posterolateral lung — B-lines, effusion, consolidation

Femoral and popliteal compression — if PE is in the differential

Abdominal windows — if trauma or haemorrhage is in the differential

Diaphragm thickening fraction — if the question is weaning

What every protocol shares

State the question before scanning. The protocol structures the answer; it does not choose the question.
Record the loading conditions. Without them the study cannot be compared with the next one.
Store the images. An unarchived study cannot be reviewed or defended (Chapter 42).
Report the study level and its exclusions. A protocol's explicit limitations belong in the report, not just in the operator's head.
Repeat. In critical illness the paired study — before and after an intervention — carries more information than any single examination.

🛑 Critical pitfall: Using a protocol designed for binary questions to make a quantitative decision. FoCUS does not grade valves, estimate filling pressures, or measure cardiac output, and reporting as though it did is the commonest documentation failure in critical care echocardiography.

🛑 Critical pitfall: Allowing the sonographer to also run the code during FEEL. Pauses double when the same person is doing both.

💡 Clinical pearl: Print the Stage 1 and Stage 2 checklists and keep them on the machine. Under pressure, operators omit the same three things — the vasoactive dose, the rhythm, and the view used for the VTI.
💡 Clinical pearl: The most transferable single number in this chapter is LVOT VTI. Teach it early; it converts every subsequent protocol from qualitative to quantitative.

References

Spencer KT, Kimura BJ, Korcarz CE, et al. Focused cardiac ultrasound: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr 2013;26:567–81.
Via G, Hussain A, Wells M, et al. International evidence-based recommendations for focused cardiac ultrasound. J Am Soc Echocardiogr 2014;27:683.e1–33.
Jensen MB, Sloth E, Larsen KM, Schmidt MB. Transthoracic echocardiography for cardiopulmonary monitoring in intensive care. Eur J Anaesthesiol 2004;21:700–7.
Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: rapid ultrasound in shock in the evaluation of the critically ill. Emerg Med Clin North Am 2010;28:29–56.
Breitkreutz R, Price S, Steiger HV, et al. Focused echocardiographic evaluation in life support and peri-resuscitation of emergency patients. Resuscitation 2010;81:1527–33.
Part 9: Adult Advanced Life Support: 2025 AHA Guidelines for CPR and ECC. Circulation 2025.